A source told Entertainment Tonight that the two fought "all the time," and explained that their22-year age gap definitely played a part, saying:

"She is really young and affected by the industry and scene at times. She is a cool girl, but Johnny is cooler and doesn't tolerate that."

The insider explained that the famous father also didn't love when the bisexual babe would hang out with her ex-girlfriend, Tasya van Ree, so she supposedly distanced herself from her old inner circle.

The confidante confessed that the Friday Night Lights alum was very hot-and-cold when it came to their union, adding:

"She can change her mind within minutes. One minute they are off and the next she decides she wants to stay. The marriage has been on the rocks since it started."

And according to the source, these issues are nothing new:

"They have been having problems for quite some time. It started a few months after they got married and it just never got better. It was extremely volatile."

Wow.

If Johnny and Amber's marriage was really this bad, maybe it's a good thing they called it quits. What do U think, Perezcious readers?!